antistatic bag - A packaging material containing anti-ESD shielding or dissipative materials to protect components from ESD damage. ESD (electrostatic discharge) The release of a charge from a metal or plastic surface that occurs when a potential difference is formed between the charged object and an oppositely charged conductive object. This electrical discharge can damage silicon chips and computer components if they are exposed to it. grounded An equipment ground provides a safe path for electrical current to flow away in the event that a device or cable is faulty. Self-grounding removes any static potential difference between a technician's clothes and body and a device they are handling, reducing the risk of damaging the component through Electrostatic Discharge (ESD). self-grounding Manual dissipation of static buildup by touching a grounded object prior to touching any electronic equipment. adapter card Circuit board providing additional functionality to the computer system (video, sound, networking, modem, and so on). An adapter card fits a slot on the PC's expansion bus and often provides ports through slots cut into the back of the PC case. Different cards are designed for different slots (PCI or PCIe). ATXA standard PC case, motherboard, and power supply specification. Mini-, Micro-, and Flex-ATX specify smaller board designs. blanking plateMetal strips that cover unused adapter slots in the case so that proper air flow is maintained within the system case. busBuses are the connections between components on the motherboard and peripheral devices attached to the computer. Buses are available in industry standard formats, each with its own advantages and disadvantages. The standard functions of a bus are to provide data sharing, memory addressing, power supply, and timing. Common bus types include PCI, PCI Express, and USB. chipsetThe chipset provides communications between different components by implementing various controllers (for memory, graphics, I/O, and so on). Historically, "fast" controllers (memory and video) were part of a "northbridge" chipset, placed close to the CPU and system memory. Slower buses were part of a "southbridge" chipset. In modern PC architecture, video and memory controllers are part of the CPU (on-die), the northbridge would mostly handle PCI Express adapters, and the southbridge would host SATA, USB, audio and LAN functions, plus PCI/PATA legacy bus support. CMOS(complementary metal oxide semiconductor) A type of integrated circuit with a wide range of applications, including static RAM (for firmware and flash memory) and imaging sensors. daughter board A circuit board that connects to the motherboard to provide extra expansion slots or connectors. Typically, these are used in slimline case designs so that adapter cards can be installed parallel to the motherboard, reducing the height of the case. expansion bus The external bus that allows additional components to be connected to the computer. expansion cards A printed circuit board that is installed in a slot on a system board to provide special functions for customizing or extending a computer's capabilities. Also referred to as adapter card, I/O card, add-in, add-on, or board. expansion slots Connection slots on the motherboard in which adapter cards can be installed to extend the range of functions the computer can perform. firmwareThis refers to software instructions stored semi-permanently (embedded) on a hardware device. Modern types of firmware are stored in flash memory and can be updated more easily than legacy programmable Read Only Memory (ROM) types. FRU(field replaceable unit) An adapter or other component that can be replaced easily and quickly by a technician on-site, without the need for repair services. Most PC and laptop components are FRUs, while the components of smartphones are not. jumper A small plastic clip containing a metal conductor that fits over two contacts to complete a circuit that configures the motherboard or adapter card one way or another. microATX Introduced in late , and is often referred to as μATX, and has a maximum size of . inches by . inches. mini-ITXA small compact board that fits the same form factor as the ATX and the micro-ATX boards. They have a maximum size of . inches by . inches. motherboard The computer motherboard, also called the system board, provides the basic foundation for all of the computer's hardware, including the processor, RAM, firmware, and expansion cards. Several motherboard standards are available, each with a different layout and associated advantages. PCI bus (Peripheral Component Interconnect bus) Introduced in with the Pentium processor, it connects the CPU, memory, and peripherals to a -bit working at MHz. PCI supports bus mastering, IRQ steering, and Plug-and-Play. Later versions defined -bit operation and MHz clock but were not widely adopted on desktop PCs. PCIe (PCI Express) An expansion bus standard using serial communications. Each device on the bus can create a point-to-point link with the I/O controller or another device. The link comprises one or more lanes (x, x, x, x, x, x, or x). Each lane supports a full-duplex transfer rate of MBps (v.), MBps (v.), or GBps (v.). The standard is software compatible with PCI, allowing for motherboards with both types of connectors. riser card A space-saving feature of some motherboards, a riser card puts the PC's expansion slots on a separate board installed at right-angles to the main board. This allows the system components to fit within a slimline case. RTC (real time clock) Part of the system chipset that keeps track of the date and time. The RTC is powered by a battery so the PC keeps track of the time even when it is powered down. If the computer starts losing time, it is a sign that the battery is failing. SFF (Small Form Factor) Motherboards and connectors that are designed to take up less space. standoffs Used to firmly attach the motherboard to the case, ensuring no other part of the motherboard touches the case. system case A plastic and metal box that houses components such as the motherboard, Central Processing Unit (CPU), memory, adapter cards, disk drives, and power supply unit. System units are also often referred to as boxes, main units, or base units. system clock The computer's timing mechanism that synchronizes the operation of all parts of the computer and provides the basic timing signal for the CPU; measured in MHz or GHz. system firmware Low-level code to allow the computer components to be initialized and load the main operating system software. system memory The main storage area for programs and data when the computer is running. DB- Although the original serial port used a -pin male D connector, most PCs today use a male DB- (-pin) port. (See also serial port.) eSATA (external Serial Advanced Technology Attachment) An external interface for SATA connections, enabling you to connect external SATA drives to PCs. host controller A hardware component of the USB subsystem responsible for recognizing when a USB device is attached or removed from the system, monitors the device status, provides power to the USB devices, and controls the flow of data between the USB host and USB devices. Lightning ports Proprietary connector and interface for Apple devices. Molex connector A power connector that is used to supply power to Parallel Advanced Technology Attachment (PATA) drives, optical drives, and SCSI drives. port (physical) A hardware connection interface on a personal computer that enables devices to be connected to the computer. RJ connector (Registered Jack connector) A connector used for twisted pair cabling. -pair network cabling uses the larger RJ- connector. Modem/telephone -pair cabling uses the RJ- connector. RS- A serial port that uses a -pin male D connector. (See also serial port). serial port Asynchronous serial transmission (RS-) is one of the oldest PC bus standards. A serial port is a legacy port that can be used to connect devices such as modems, mice, and Uninterruptible Power Supplies (UPS). Serial ports transmit data bit-by-bit using a single data line at a speed of up to about Kbps. Although the original serial port used a -pin male D connector, most PCs today use a male DB (-pin) port. The serial port is now little used but does provide an "out-of-band" means of configuring network appliances such as switches and routers. surround sound Placement of multiple speakers positioned around the listener to provide a cinematic audio experience.